diff --git a/apps/multiplatform/common/src/androidMain/kotlin/chat/simplex/common/platform/Images.android.kt b/apps/multiplatform/common/src/androidMain/kotlin/chat/simplex/common/platform/Images.android.kt
index 4f47fda130..1a3703822d 100644
--- a/apps/multiplatform/common/src/androidMain/kotlin/chat/simplex/common/platform/Images.android.kt
+++ b/apps/multiplatform/common/src/androidMain/kotlin/chat/simplex/common/platform/Images.android.kt
@@ -21,12 +21,19 @@ import java.net.URI
 import kotlin.math.min
 import kotlin.math.sqrt
 
+private const val MAX_IMAGE_DIMENSION = 4320
+
 actual fun base64ToBitmap(base64ImageString: String): ImageBitmap {
   val imageString = base64ImageString
     .removePrefix("data:image/png;base64,")
     .removePrefix("data:image/jpg;base64,")
   return try {
     val imageBytes = Base64.decode(imageString, Base64.NO_WRAP)
+    val options = BitmapFactory.Options().apply { inJustDecodeBounds = true }
+    BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.size, options)
+    if (options.outWidth <= 0 || options.outHeight <= 0 || options.outWidth > MAX_IMAGE_DIMENSION || options.outHeight > MAX_IMAGE_DIMENSION || options.outHeight > options.outWidth * 256) {
+      return errorBitmap.asImageBitmap()
+    }
     BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.size).asImageBitmap()
   } catch (e: Exception) {
     Log.e(TAG, "base64ToBitmap error: $e")
diff --git a/apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/model/ChatModel.kt b/apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/model/ChatModel.kt
index 76a9ab4c16..8c27db443b 100644
--- a/apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/model/ChatModel.kt
+++ b/apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/model/ChatModel.kt
@@ -3834,7 +3834,7 @@ object MsgReactionSerializer : KSerializer<MsgReaction> {
       when(val t = json["type"]?.jsonPrimitive?.content ?: "") {
         "emoji" -> {
           val msgReaction = try {
-            val emoji = Json.decodeFromString<MREmojiChar>(json["emoji"].toString())
+            val emoji = decoder.json.decodeFromString<MREmojiChar>(json["emoji"].toString())
             MsgReaction.Emoji(emoji)
           } catch (e: Throwable) {
             MsgReaction.Unknown(t, json)
@@ -4276,7 +4276,7 @@ object MsgContentSerializer : KSerializer<MsgContent> {
         when (t) {
           "text" -> MsgContent.MCText(text)
           "link" -> {
-            val preview = Json.decodeFromString<LinkPreview>(json["preview"].toString())
+            val preview = decoder.json.decodeFromString<LinkPreview>(json["preview"].toString())
             MsgContent.MCLink(text, preview)
           }
           "image" -> {
@@ -4294,11 +4294,11 @@ object MsgContentSerializer : KSerializer<MsgContent> {
           }
           "file" -> MsgContent.MCFile(text)
           "report" -> {
-            val reason = Json.decodeFromString<ReportReason>(json["reason"].toString())
+            val reason = decoder.json.decodeFromString<ReportReason>(json["reason"].toString())
             MsgContent.MCReport(text, reason)
           }
           "chat" -> {
-            val chatLink = Json.decodeFromString<MsgChatLink>(json["chatLink"].toString())
+            val chatLink = decoder.json.decodeFromString<MsgChatLink>(json["chatLink"].toString())
             MsgContent.MCChat(text, chatLink)
           }
           else -> MsgContent.MCUnknown(t, text, json)
diff --git a/apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/FramedItemView.kt b/apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/FramedItemView.kt
index f36da6c908..9a9626b1b8 100644
--- a/apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/FramedItemView.kt
+++ b/apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/FramedItemView.kt
@@ -437,7 +437,10 @@ fun PriorityLayout(
   ) { measureable, constraints ->
     // Find important element which should tell what max width other elements can use
     // Expecting only one such element. Can be less than one but not more
-    val imagePlaceable = measureable.firstOrNull { it.layoutId == priorityLayoutId }?.measure(constraints)
+    // Constrain max image height to prevent crashes and scroll issues from images with extreme aspect ratios
+    val maxImageHeight = (constraints.maxWidth * 2.33f).toInt().coerceAtMost(constraints.maxHeight)
+    val imageConstraints = constraints.copy(maxHeight = maxImageHeight)
+    val imagePlaceable = measureable.firstOrNull { it.layoutId == priorityLayoutId }?.measure(imageConstraints)
     val placeables: List<Placeable> = measureable.map {
       if (it.layoutId == priorityLayoutId)
         imagePlaceable!!
diff --git a/apps/multiplatform/common/src/desktopMain/kotlin/chat/simplex/common/platform/Images.desktop.kt b/apps/multiplatform/common/src/desktopMain/kotlin/chat/simplex/common/platform/Images.desktop.kt
index d3b8cdcb58..ee00e1649f 100644
--- a/apps/multiplatform/common/src/desktopMain/kotlin/chat/simplex/common/platform/Images.desktop.kt
+++ b/apps/multiplatform/common/src/desktopMain/kotlin/chat/simplex/common/platform/Images.desktop.kt
@@ -21,12 +21,26 @@ import kotlin.math.sqrt
 private fun errorBitmap(): ImageBitmap =
   ImageIO.read(ByteArrayInputStream(Base64.getMimeDecoder().decode("iVBORw0KGgoAAAANSUhEUgAAAEAAAABACAYAAACqaXHeAAAAAXNSR0IArs4c6QAAAKVJREFUeF7t1kENACEUQ0FQhnVQ9lfGO+xggITQdvbMzArPey+8fa3tAfwAEdABZQspQStgBssEcgAIkSAJkiAJljtEgiRIgmUCSZAESZAESZAEyx0iQRIkwTKBJEiCv5fgvTd1wDmn7QAP4AeIgA4oW0gJWgEzWCZwbQ7gAA7ggLKFOIADOKBMIAeAEAmSIAmSYLlDJEiCJFgmkARJkARJ8N8S/ADTZUewBvnTOQAAAABJRU5ErkJggg=="))).toComposeImageBitmap()
 
+private const val MAX_IMAGE_DIMENSION = 4320
+
 actual fun base64ToBitmap(base64ImageString: String): ImageBitmap {
   val imageString = base64ImageString
     .removePrefix("data:image/png;base64,")
     .removePrefix("data:image/jpg;base64,")
   return try {
-    ImageIO.read(ByteArrayInputStream(Base64.getMimeDecoder().decode(imageString))).toComposeImageBitmap()
+    val bytes = Base64.getMimeDecoder().decode(imageString)
+    val stream = ImageIO.createImageInputStream(ByteArrayInputStream(bytes))
+    val reader = ImageIO.getImageReaders(stream).next()
+    reader.setInput(stream)
+    val width = reader.getWidth(0)
+    val height = reader.getHeight(0)
+    if (width <= 0 || height <= 0 || width > MAX_IMAGE_DIMENSION || height > MAX_IMAGE_DIMENSION || height > width * 256) {
+      reader.dispose()
+      return errorBitmap()
+    }
+    val image = reader.read(0)
+    reader.dispose()
+    image.toComposeImageBitmap()
   } catch (e: Throwable) {
     Log.e(TAG, "base64ToBitmap error: $e")
     errorBitmap()